N-Methoxy-N,1-diMethyl-1H-pyrazole-3-carboxaMide synthesis

Yield:875553-40-5 100%

Reaction Conditions:

with benzotriazol-1-ol;1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride;triethylamine in dichloromethane at 20; for 22 h;

Steps:

31.1

1) 1-Methyl-1H-pyrazole-3-carboxylic acid N-methoxy-N-methylamide 1-Hydroxybenzotriazole (2.37 g), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (6:79 g), triethylamine (13.4 mL), and N, O-dimethylhydroxylamine hydrochloride (2.93 g) were added to a solution of 1-methyl-1H-pyrazole-3-carboxylic acid (2.025 g) in dichloromethane (80 mL) at room temperature, and the resultant mixture was stirred for 22 hours. Water and chloroform were added to the reaction solution, and the mixture was partitioned. The organic layer was washed with saturated saline, and then dried over anhydrous sodium sulfate. After separation by filtration, a residue obtained by evaporating the solvent under reduced pressure was purified by silica gel column chromatography (acetone-chloroform), to obtain 1-methyl-1H-pyrazole-3-carboxylic acid N-methoxy-N-methylamide (2.78 g, quantitative) as an oily product. ¹H-NMR(400MHz, CDCl₃)δ: 3.43(3H, br s), 3.75(3H, s), 3.97(3H, s), 6.76(1H, d, J=2.4Hz), 7.36(1H, d, J=2.4Hz). FAB-MSm/z: 170(M+H)⁺.

References:

EP1785418,2007,A1 Location in patent:Page/Page column 50